Geochronology

Geochronology

Abstract:
The Utah Geochronology Database contains ages and related dating information of sampled geologic materials (soil and rock) using argon (40Ar/39Ar), luminescence (TL, IRSL, and OSL), or radiocarbon (14C) dating methods and were analyzed for a variety of geologic-related projects by the tah Geological Survey (UGS) and others. These ages were used in fault trench investigations to determine the timing of past earthquakes and to develop other paleoseismic parameters, in the dating of basalt flows for eruption histories and in dating fault movement, and similar projects. Since geochronologic methods have significantly evolved and improved through time, older data is often not as reliable or usable as more recently dated materials. The user should use caution in using this data, as significant knowledge and experience is often needed to interpret and apply geochronologic data to projects correctly. A web mapping application for the database is available. As the database is expanded in the future, age results from other geochronologic dating methods are anticipated to be added. Various geochronologic data from geologic mapping projects that may not have yet been included in the database may also be available. Donations of geochronologic data in Utah are appreciated, so that these data can be permanently archived and discoverable and available to all users. For more details contact Steve Bowman from UGS at SteveBowman@utah.gov or 801-537-3304.

Argon

Argon: Argon–Argon (40Ar/39Ar) dating is a relative radiometric dating method that relies on neutron irradiation from a nuclear reactor to convert a stable form of potassium (39K) into the radioactive 39Ar, is primarily used on metamorphic and igneous minerals, and generally replaces the older potassium-argon (K/Ar) method. The Geoscience.GeochronArgon data layer represents the argon (40Ar/39Ar) dating data in the Utah Geochronology Database.

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Updates

November 2017

Luminescense

Luminescence: Luminescence dating refers to a group of methods, including optically stimulated luminescence (OSL), infrared stimulated luminescence (IRSL), and thermoluminescence dating (TL), that determine how long ago mineral grains were last exposed to sunlight or sufficient heating. It is commonly used by geologists and archaeologists to determine when that event occurred, such as surface fault rupture from an earthquake. Optical dating typically refers to OSL and IRSL, but not TL.The Geoscience.GeochronLuminescence data layer represents the luminescence (OSL, IRSL, and TL) dating data in the Utah Geochronology Database.

Downloads and Web Services

Updates

November 2017

Radiocarbon

Radiocarbon: Radiocarbon dating is a radiometric dating method for determining the age of an object containing organic material by using the properties of the radioactive isotope of carbon (14C). Measurement of radiocarbon was originally performed using beta-counting devices, which counted the amount of beta radiation emitted by decaying 14C atoms in a sample. Accelerator mass spectrometry (AMS) is now used, and counts all of the 14C atoms in the sample, and not just the few that happen to decay during the measurement interval and can be used with significantly smaller samples (such as individual plant seeds), and gives results more quickly. The Geoscience.GeochronRadiocarbon data layer represents the radiocarbon (C or AMS) dating data in the Utah Geochronology Database.